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Full catalog/PET_PU_3H025
PET_PU_3H025·v001·dataset

How much water land could lose, 3-hourly (v1, 0.25 deg)

RM-OBS/PU Potential Evapotranspiration and Supporting Forcing L4 3-hourly 0.25x0.25 degree V001 (PET_PU_3H025) at GES DISC
atmosphere NASA GES_DISC Level 4
In plain English

What it measures. Estimates of potential evapotranspiration, meaning how much water the land could lose to the air through evaporation and plant transpiration if water were freely available, every three hours.

How it's made. Calculated by Princeton University from blended weather and surface-radiation data using three standard methods, rather than measured by one satellite. This is the first version of the dataset.

How & where you'd use it. Supports drought monitoring, irrigation and water-resource planning, and studies of how much moisture the landscape demands.

What's measured

ATMOSPHERE › ATMOSPHERIC PRESSURE › SURFACE PRESSUREATMOSPHERE › ATMOSPHERIC RADIATION › HEAT FLUXATMOSPHERE › ATMOSPHERIC RADIATION › NET RADIATIONATMOSPHERE › ATMOSPHERIC TEMPERATURE › SURFACE TEMPERATUREATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR INDICATORS › HUMIDITY › SPECIFIC HUMIDITYATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR PROCESSES › EVAPOTRANSPIRATION › POTENTIAL EVAPOTRANSPIRATIONATMOSPHERE › ATMOSPHERIC WINDS › SURFACE WINDS › WIND SPEED

Coverage & cadence

  • Time span1984-01-01 → 2006-12-31
  • Measured byRM-OBS/PU (NOT APPLICABLE)
  • Processing levelLevel 4
  • Spatial extent-180, -60, 180, 90
  • StatusCOMPLETE

What you can do with it

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
Official description

The Princeton University MEaSUREs Potential Evapotranspiration (PET) dataset provides a set of estimates of PET based on near surface meteorology and surface radiation data derived from a combination of reanalysis, satellite and gridded gauge data. The rationale of the project is to reduce the error from the input meteorological forcing and provide a variety of widely-used PET methods for different research and application purposes. PET is estimated using three methods: Penman open-water method (Penman), Priestley-Taylor method (PT), Reference crop evapotranspiration using the UN Food and Agricultural Organization approach (FAO). The Penman equation assumes PET occurs from an open water surface and calculates PET based on observations of surface net radiation, near-surface air temperature, wind speed, and specific humidity (Shuttleworth, 1993). The PT equation calculates PET based on surface net radiation and near-surface air temperature and does not account for the aerodynamic component (Priestley and Taylor, 1972). The FAO equation is a specific application of the Penman-Monteith equation for crop and short-grass reference surfaces and is based on surface net radiation, near-surface air temperature, wind speed, and specific humidity (Allen, 1998). This first version of dataset is estimated at a 3 hourly temporal resolution and 0.25x0.25 degrees spatial resolution globally, spanning the 23-year period 1984-2006. Datasets are stored as a 3-dimensional array with dimension 720 x 1440 x 8 for each day, in NetCDF-4 format.

Get the data

pet_pu_3h025_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="PET_PU_3H025",
    version="001",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from GES_DISC
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.